Lopy-Lopy Communication Distance is too short !!!

Hi Guys,
I was setting up a Lopy in my Home with External Antenna (Typically placed from Second Floor Window - Living in Chennai City in India) and one in my Car with an External Antenna trying the below configuration's on the both the Lopy

@constantinos
I have already tried the configurations - nothing fruitful.

@Clemens
Range depends on the kind of inteference you have in your street,I have literally 3 different companies cell phone towers within 1 KM range around my area and this is quite obvious in most of the cities in India.
I tested it in a straight road with minimal interferences and able to get it around 400m.
But if we are to use it in a Metro/Cosmo Politan citiy with high interference, then we need to place the base station/reciever with multi channel in a high raise building with a good Antenna covering a range around 3 miles
Now the Challenge is whether the same Lora Chip with single Channel Gateway (Lopy) is capable of doing atleast the minimal coverage is what i am testing.
From the test,my simple inference is that Lora really works well in remote areas where there is little or no interference,so i dropped the asset tracking usecase of Lopy-Lopy where i am much disappointed.

I used a pair of LoPys with the "LoRa/Sigfox Antennen-Kit" http://www.exp-tech.de/lora-sigfox-antenna-kit . and frequency=868000000, tx_power=14, bandwidth=LoRa.BW_125KHZ, sf=7 I reached around 450 m in the same street without line-of-sight. I think you will get no more distance with obstacles in between.

So in the end it seems that if both sensor and gateway are on releases up to 1.6.3.b1 or 1.6.4b1 and newer the communication works well. I am now running both on 1.6.7.b1.

In 1.6.4.b1 following change was implemented:
esp32: Enable all spreading factors and bandwidths supported by the SX1272.
Maybe this is the reason for incompatibility between some (different) versions.

I have gateway - sensor system based on LoPy. Until yesterday I was using releases from february. Yesterday I performed upgrade of both gateway and sensor and to my surprise LoRa message (16 Bytes) made it to the gateway only rarely. So I started downgrading the firmware incrementaly and found out that last release on which the communication works well is 1.6.3.b1. Not sure what is happening, will do more testing today.

@livius
The Antenna that shipped along with my Lopy.
I Placed it on the Windowsill
In the car I kept it near my Gear where i plugged it to the USB and started moving in my Car from my Home.
There are quite a number of buildings and other Cell Phone Towers near my Home and obviously DTH Antenna's on top every Home.

@livius - I am defenitely aware of the above said factor's & the line of sight but how to apply Lora in densely populated cities with quite a lot of inteference ?
I thought of tracking my Car within a particular range within the city atleast 2-3 Miles which can't be always in the line of Sight....